Prefabricated reinforced concrete foundation is a rather practical and high-quality structure that has been used in construction not so long ago. It is a monolith in which iron blocks are mounted. Using this technology in construction, you will noticeably save not only installation time, but also money. In our article we will try to tell everything about what a reinforced concrete structure is, what types it is, where it is used, and so on.
General information about monoliths
Before you start installing precast concrete foundations, it is recommended to become more familiar with this design, since the quality of the constructed building may depend on this knowledge. For example, among the monoliths there are lightweight blocks with air voids. Their applicationjustified only if the height of the building will be no more than one floor.
As for the laying of monoliths, it is carried out on an ordinary cement mortar - this helps to eliminate drafts inside the room, as well as moisture in the basement floors. In addition, strip foundations are also recommended to be protected with a special waterproofing that prevents the penetration of moisture into the room.
A significant disadvantage of reinforced concrete structures is their heavy weight. As a rule, the installation of precast concrete foundations is possible only with the help of special equipment, such as a crane. However, for the manufacture of some modern monoliths, lightweight materials and modern technologies are used to lighten the weight of the structure up to 30 kg.
Conditions for the use of reinforced concrete structures
Prefabricated-monolithic reinforced concrete foundations are massive structures that can be used for the construction of multi-storey buildings or private houses. However, every builder knows that the foundation is the most important element of any building, so it must be done with the highest quality. It is allowed to install reinforced concrete structures only if the soil on the site and the future structure will meet the following characteristics:
- brick, concrete, stone, the density of which does not exceed 1300 kilograms per cubic meter, is used as a material for the construction of walls;
- during the construction of the building, it is planned to use heavy reinforced concrete floors, which will givedesign strength;
- the soil along the perimeter of the site has a heterogeneous structure (it is desirable that it contains gravel, crushed stone, screenings and other hard rocks);
- the foundation structure will later support the basement or basement.
It is strongly not recommended to install a precast concrete foundation under the column in places with peaty or silty soil, because the structure will sooner or later push through the soil layer and the building will squint down. In addition, groundwater must be at a depth of at least three meters, especially when it comes to building a basement. Otherwise, excessive moisture will eventually penetrate the walls of the structure, which is fraught with moldy walls or even their collapse.
Strip precast foundation technology
Usually, strip precast concrete foundation is used for the construction of the basement floor, which is planned to be put into operation. This design consists of blocks and prefabricated slabs, which form a full-fledged floor. Since it will be quite difficult to pour such a foundation on your own, most experienced builders recommend using concrete monoliths made of reinforced concrete and cement-sand mortar with vertical seams.
As for the iron element, the monolith does not consist entirely of metal - it just uses reinforcement, which gives the structure additional strength and simplifies the assembly process. In addition, tapethe foundations also have fairly good mobility, and the stabilization of the monoliths occurs due to a special reinforced belt, consisting of a movement and several shock-absorbing elements. Such plates are suitable for the construction of cottages and multi-storey buildings.
Foundation properties and block selection
Did you decide to purchase prefabricated reinforced concrete glass-type foundations? Are you sure that this type of construction is suitable for your region? For example, for the construction of buildings in cold areas, it is strongly recommended to purchase blocks with increased frost resistance. This quality is achieved through the use of special additives during manufacture. Well, if you plan to build a building on soil with high acidity, then it is best to use a foundation wall block, which includes crushed granite, which is resistant to an acidic environment.
Also, factory-made foundations come in a huge variety of sizes and shapes. For large buildings, structures with large dimensions are used that can withstand a weight of several hundred tons. Of course, for their installation will have to use special equipment. Well, for a private house, blocks of rather small sizes are provided that can be installed manually.
In the introduction, we mentioned that you can save a lot on the use of reinforced concrete foundations, but it’s worth clarifying that they save not on the cost of structures, but on labor. Usually onea monolith will cost about 30 percent more than buying building materials separately. But installation is carried out several times faster than construction work. Although do not forget that the blocks will also require an additional layer of waterproofing, which is quite expensive.
When choosing a precast concrete foundation, GOST is very important. If you purchase material of dubious quality, then the building may completely collapse over time. To prevent this from happening, it is necessary to purchase only certified products with a quality guarantee. It is best to buy monoliths at construction bases, since in ordinary stores their prices are usually overpriced by 40 or even 50 percent.
Preparatory work
Before the installation of precast concrete foundation blocks, the site must be cleared. In addition, it is necessary to mark the site with a construction cord and metal stakes. As a rule, each side of the construction site is two meters longer than the required size. Marking is a very important stage of construction, since even the slightest mistake can lead to the fact that the parts simply do not fit.
In order for the corners in the markup to be as even as possible (90 °), it is necessary to use a building level, attaching it to two driven pegs. Once you are sure that the markings are as level as possible, drive the stakes in as deep as possible tothey didn't budge even after the rain. The accuracy of the calculations can be checked using the diagonal by drawing it from the top corner to the opposite bottom. Thus, two right-angled triangles will be obtained, which must obey the Pythagorean theorem.
Trench work
As soon as the markup is ready, you can start construction work. If your choice is a precast concrete foundation for the column, then during the preparation of the trench it is necessary to dig a hole of suitable depth. All work can be done with your own hands or using special earthmoving equipment. Be sure to check the depth of the trench from time to time, which should always remain at the initial level. With excessive deepening, you can additionally pour a layer of rubble into the pit (up to 10 centimeters) and tamp it well.
As soon as the foundation pit is ready, you can start laying a sand cushion, the layer of which should not exceed 15 centimeters, and the width should be 20-30 centimeters more than the width of the reinforced concrete block. As soon as the material is poured, pour it with water and tamp it well. After that, it will be necessary to install a waterproofing layer. To do this, you can use a special plastic film, which can be purchased at any hardware store. In some cases, waterproofing is also laid on top of a reinforced concrete foundation.
Tools and materials for work
To install a precast concrete foundation,it is necessary to prepare in advance all the necessary materials and tools. Otherwise, in the process of work, you will have to constantly be distracted by something. To install the foundation you will need:
- waterproofing material;
- design size blocks;
- reinforced concrete pads;
- reinforcing bars;
- masonry mortar.
Depending on individual preferences, this list of materials can be significantly expanded. For example, if you decide to use crushed stone bedding, you will have to take this into account at the planning stage. In addition, you will also need to acquire many tools, the list of which looks something like this:
- concrete mixer or some container for making mortar;
- metal pegs, nylon cord and tape measure;
- flat base rail for leveling grout;
- building level (level) and plumb line;
- welding machine, grinder with disc;
- scrap, trowel, trowel, shovels.
It is easy to guess that the list of tools directly depends on the materials that are planned to be used during the construction process. Therefore, if you decide to add some element to the foundation, be sure to take this into account at the planning stage so that you do not have to look for precious tools to work with the material later.
Installation of block pillows
In order to improve the bearing performance of the precast concrete strip foundation,it is necessary to install a layer of block pillows under it. They are laid out on a layer of waterproofing, which comes after the sand cushion. The design is designed to increase the area of support and the stability of the foundation. Installation is carried out using a conventional mortar, which is laid out on a waterproofing layer.
Do not forget that a flat base is the key to the reliability of any design. If the layer of block pillows is installed crookedly, then the entire foundation and building will also be skewed to one side. The horizontalness of the surface can be controlled using a level or a conventional building level. If the installation was not done correctly, do not be afraid to dismantle the unit and reinstall it.
Metal reinforcement with a cross-sectional area of at least 30 millimeters is laid on the upper plane of the pillows. The parts are cut using a conventional grinder with a disk, and a conventional welding machine will be indispensable for installation. As for docking, it must be overlapped. In this case, the length of the weld should be approximately 10 diameters of the rod - 30 centimeters. From above, the reinforcement is covered with a layer of mortar.
Assembly of reinforced concrete blocks
It is necessary to install any series of precast concrete foundations in a checkerboard pattern, otherwise the structure will simply collapse as a result of a strong impact on the corner. When laying the blocks, a cement-sand mortar is used, approximately 20 millimeters thick, which should be constantly leveled withbuilding level. As you install, the joints should also be tightly filled with mortar.
Do not forget about the need to leave special openings between the blocks in order to then carry out means of communication or sewerage. Once the sleeves are installed in the wall, all seams and holes must be sealed with mortar. Otherwise, drafts and moisture inside the house cannot be avoided.
Also, when mounting the blocks, it is strongly recommended to use a dressing in rows. especially at the point of contact between internal and external walls. Well, high-quality waterproofing is one of the most important values, since contact with a humid environment can be detrimental to the foundation. That is why in the ground part of the foundation it is worth hammering all the grooves of the blocks with dense soil. It is best to use clay for this purpose or the same earth that will remain on the site after digging the pit.
Video and conclusion
We hope you now have a better understanding of what constitutes a precast concrete foundation. If you have any questions about this or you do not fully understand the installation process of a reinforced concrete structure, we recommend that you watch a short video in which the author talks about the construction technology based on reinforced concrete blocks. This information will be relevant for the most part to novice builders, although it is quite possible that professionals will also learn something useful from the video.
We hope ourthe article helped you understand all the features of working with a prefabricated foundation. Of course, such a technology will cost much more than the construction of a conventional structure, but there is no reason to doubt the quality and reliability of reinforced concrete blocks. Be sure that the cost of buying building materials will more than pay off on the wages of builders.
